It is well known to regenerate the abovementioned resin beads by separating them by hydraulic action and then treating the anion resin beads with sodium hydroxide and treating the cation resin beads with sulphuric acid or hydrochloric acid. The two types are then re-mixed and held in a vessel ready for re-use.
The present state of practised art is exemplified in British patents GB2027610B, GB2094174B and GB2117264B, all of which are owned by the applicant for a patent for the present invention.
The efficiency of the inventions described and claimed in the above mentioned patents is such that resin beads that have been regenerated thereby reduce the contamination in water to less than 0.3%. However, even higher standards of water purity are now needed so as to enable its use in the semi conductor chip industry. Thus the present invention seeks to provide an improved method of regenerating anion and cation resins for re-use in the purification of water.